The Biometry and Field Studies Branch is the Statistical Coordinating Center for the ongoing clinical trial of the behavioral and cognitive side effects of phenobarbital used for prevention of febrile seizure recurrence. The accrual of patients has been completed, with 367 patients on study. Follow-up with psychometric testing will continue through FY '89. During this fiscal year, one interim analysis of the data was performed for evaluation by the Performance and Safety Monitoring Committee. In addition, extensive data editing is continuing, creation of structured files for analysis is completed, the distributions of the outcome variables have been examined and strategies are being developed for final analysis including the development of statistical methods for the analysis of language development data, play maturity data, activity level, and the recurrence rate of febrile seizures. *(This study reports the DNB/DCDND/NINCDS contract study entitled: "Behavioral and cognitive side effects of phenobarbital used for prevention of febrile seizure recurrence." The project officer is Dr. Deborah G. Hirtz, DNB, DCDND, NINCDS, and the contractor of the study is the University of Washington.)